Question 1092588: A photographer increases the side of a square in the ratio 4:5. By what percentage are the sides increased? Answer by Theo(13342) (Show Source):
You can put this solution on YOUR website! let x equal the original length of the side of the square.
let y equal the new length of the side of the square.
you get x/y = 4/5
cross multiply to get 5x = 4y
solve for y to get y = 5x/4 = 5/4 * x
5/4 * x is equivalent to (4/4 + 1/4) * x which is equal to 1 * x + 1/4 * x.
the original length of the side is increased by 1/4 * the length of the original side.
that would be equal to 25% of the length of the original side.
another way of getting to the same answer is:
y = 5/4 * x = 1.25 * x
increase percent is equal to (1.25 * x - x) / x = .25.
multiply that by 100 to 25%.
assume the original length of the side is 100.
increase that by 25% and the length of the new side is 125.
the ratio of the original length to the new length is 100 / 125 which simplifies to 4/5 when you divide both numerator and denominator by 25.
